THR LARV^ OF HYOROECIA CRINANKNSIS. 



177 



The larvae of Hydroecia crinanensis and that of Apamea leucostigma 



(fibrosa). 



By Eev. C. E. N, BUREOWS, F.E.S. 



On June 26th, 1919, I received from Mr. L. A. E. Sabine eight 

 larvaB taken from within the leaf stems of 7r/.s pseiulacorns in Co. Sligo. 

 It will be remembered that last year Mr. Sabine found the larvae of 

 Hydroecia crinanensis feeding in the interior of Iris stems and his dis- 

 covery was duly reported in our Magazine for January last, at page 12. 

 This account is so complete that it requires no further- enlargement. 



These eight larvae sent by Mr. Sabine this year were taken under 

 the same conditions, but he took a larger number and was able to send 

 me some for description. I felt scarcely capable of so delicate a busi- 

 ness but determined to do my best. I soon found that it would be 

 difficult. The larvae were filthy in their habits. The soft, semi-liquid 

 Iris pulp seemed to be merely chewed, or passed unchanged through 

 the body. The larvae would not remain still, and when I sought to 

 restrain them bit my fingers fiercely. So I, in desperation, blew them ! 

 This done I felt certain that I was dealing not with one species, but 

 with two. I had up to this point supposed that I had before me the 

 same larvae, but perhaps in different stages, for it was evident that some 

 at least were not full grown. Now I felt myself in a difficulty, which 

 however was quickly relieved by the receipt of a letter from Mr. Sabine 

 beseeching me to bestow special care upon the " dark " larvae as they 

 were not H. crinanensis, but some different species and he had found 

 only one more than the four he had sent to me. I wrote " by return " 

 confessing what I had done. He searched diligently and found a few 

 more of these strangers — which in the end proved to be Apamea leucos- 

 tigma. I need scarcely say that two pupte of H. crinanensis which I 

 handed to Mr. Mera in due course produced H. crinanensis. 



The next business was to get the larv® reliably described. This I 

 felt unequal to doing. So I called in the help of my old and valued 

 friend, Mr. A. W. Bacot, who amongst other abilities retains that of de- 

 scribing lepidopterous larvfe. 



Mr. Sabine supplies me with the life descriptions which are neces- 

 sary to complete those of blown specimens. 



H. crinanensis. — " To me the colour of crinanensis larvae seems to 

 be greyish-white (sometimes tinged with pinkish or more rarely with 

 purplish) with distinct pinkish longitudinal bands. "When nearly full 

 fed the pinkish colour becomes much duller and fainter, the greyish 

 white ground colour predominating more." 



A. leucostigma. — "The ground colour is reddish brown with very 

 faint whitish lines. 



Mr. Bacot sends me the followmg reports : — 



" Note on the differences observed in structure and markings 

 between blown specimens of the larvae of Hydroecia crinanensis and 

 Ajjamea leucostigma in their penultimate skins." 



H. CRINANENSIS. 



" Markings." — Ground colour pale whitish-grey with two broad 

 dusky dorSal bands, darker in shade, but approximately the same hue 

 as the ground colour. These dorsal bands are separated by a median' 

 band of the ground colour of about the same width. ; There is a narrow 



OCTOBER, 1919. 



